Wall and floor cavitation cleaner

ABSTRACT

The invention concerns a method and an apparatus for the ultrasound-aided cleaning of stationary utility surfaces, comprising one or more ultrasonic generators ( 1 ), ultrasonic transducer devices ( 2 ) and one or more sonotrodes ( 3 ) which are substantially of an areal configuration, wherein the unit of the sonotrode ( 3 ), the ultrasonic transducer device ( 2 ) and the generator ( 1 ) can be guided in mobile fashion on a fluid cushion delimited by a sealing lip system ( 8, 9 ), over the utility surface to be cleaned.

[0001] The invention concerns a cleaning apparatus for the ultrasound-aided cleaning of stationary utility surfaces, comprising an ultrasonic source and an ultrasonic transmitter connected thereto, hereinafter also referred to as the ultrasonic transducer.

[0002] It is known that suitable ultrasonic vibrators on either a piezoelectric or an electrostrictive basis, by means of mechanical amplitude transformation devices coupled thereto, can be used to introduce ultrasonic vibrations axially into suitably cylindrical—at least axially symmetrical bars or disks. It is known for those bars to be expanded mushroom-like at the end in order thereby to increase the size of the contact surface at which the ultrasound is outputted, or to increase the amplitude involved. Configurations of that kind however suffer from the disadvantage that the ultrasound is delivered in more or less punctiform manner and that it is generally necessary for the corresponding bars or posts to be dipped into the fluid and for the article to be cleaned then to be moved into the proximity of the bar and/or post. Hitherto however there are no known technical ways of applying ultrasound over a surface area to open floor or wall surfaces and holding the cavitation medium locally in the region of application of the ultrasound.

[0003] The object of the present invention is to provide a cleaning apparatus of the kind set forth in the opening part of this specification, with which even relatively large surfaces can be cleaned as effectively as possible.

[0004] In accordance with the invention, that object is attained by a cleaning apparatus of the kind set forth in the opening part of this specification, having a fluid film unit which is at least indirectly connected to the ultrasonic transmitter and which is adapted to produce or hold a fluid film between the ultrasonic transmitter and a surface to be cleaned.

[0005] Preferably the ultrasonic source and the ultrasonic transmitter include at least one ultrasonic generator, at least one ultrasonic transducer device and at least one sonotrode, wherein the fluid film unit has a sealing device which is connected to the sonotrode, the ultrasonic transducer device and the ultrasonic generator and which is adapted to maintain a fluid cushion between the sonotrode and a surface to be cleaned.

[0006] The sealing device preferably includes a sealing lip system which is adapted to guide a delimited fluid cushion in mobile manner over a utility surface to be cleaned and which is preferably at least of a two-shell nature.

[0007] In a cleaning apparatus with a central sonotrode, the central sonotrode preferably has a feed means for cleaning fluid.

[0008] In addition the fluid film unit preferably includes suction removal means for sucking away excessive fluid. The suction removal means are preferably provided within the sealing lip system.

[0009] In a cleaning apparatus having a central sonotrode with a free end, the free end of the central sonotrode is preferably designed in the form of a bar-shaped flexural vibrator. If the central sonotrode has an end face which is towards the surface to be cleaned, that end face is preferably substantially rectangular.

[0010] In a preferred variant the cleaning apparatus has a handle which permits easy displacement of the ultrasonic cleaning apparatus over the utility surface to be cleaned.

[0011] In addition the cleaning apparatus preferably has a power regulator for ultrasonic power to be delivered, which is preferably operable from the handle.

[0012] The cleaning apparatus preferably includes an adjusting device for an amount of fluid which is to be supplied and/or sucked away. That is preferably adjustable from the handle.

[0013] Preferably the cleaning apparatus has a limit value unit which is adapted to set and detect limit values for switching off the supply of power and fluid.

[0014] An alternative cleaning apparatus with a cleaning end face which is towards a surface to be cleaned is distinguished in that the cleaning end face is in the form of an array of individually excited sonotrodes each with a round end face.

[0015] Meaningful combinations and advantages of the above-discussed features are described hereinafter.

[0016] For generating ultrasound over a surface, a flexural beam is preferably coupled to the end of the ultrasound-transmitting sound transducer, which beam is tuned to the resonance frequency of the ultrasound used and can then be excited to produce flexural vibrations in the ultrasonic range. In a development of the concept of the invention, instead of the flexural beam, it is also possible to provide a suitably dimensioned disk which is also excited by way of an ultrasonic sonotrode. Both the beam vibrator and also the plate-type vibrator are preferably of a rectangular shape so that a cleaning system of that kind can also be used to clean room and facade corners of a right-angled configuration. In order now to be able to produce cavitation at the surface to be cleaned, the flexurally vibrating beam or the flexurally vibrating plate, and in a preferred embodiment also the ultrasound-conducting sonotrode, is provided with a central bore, by way of which the fluid which is suited to the cleaning problem involved is supplied. At the same time the flexural vibrator (beam/plate) is supported with the ultrasonic transducer in a frame so that the ultrasonic vibrations generated are not transmitted thereto. For that purpose, the system can be supported and fixed at the vibration nodes of the ultrasonic resonance system by way of suitable mechanical connections (for example pressing in or shrinking in mounting rings). That mounting frame is provided at its periphery with a highly flexible sealing lip which is resistant to abrasion and which preferably comprises silicone rubber or polyurethane (Vulkollan) so that the fluid supplied can be held in the form of a fluid cushion between the flexural vibrator and the surface to be cleaned. In order to prevent excess fluid from flowing out in the traversing movement of the cleaning head, in accordance with the invention a further sealing lip is provided in circumferential relationship with the first sealing lip, wherein the intermediate space between the first and second sealing lips is connected to a suction device so that fluid which issues from the first sealing lip can then be sucked away by way of the suction effect in the intermediate space between the first and second sealing lips. In accordance with the invention that fluid which is sucked away is fed to the fluid circuit again by way of a suitable filter device so that the process entails the minimum possible fluid loss. In accordance with the invention moreover the feed of fluid is controlled by way of the regulating circuit of the sonotrode, or by way of suitable microswitches in the region of the sealing lips, in order to ensure that there is always a sufficient fluid cushion present for the cavitation process, and on the other hand in order to ensure that, when lifting the cleaning head off the surface to be cleaned, the feed of fluid is interrupted in order to avoid an uncontrolled discharge flow thereof or to protect the system and the article being cleaned from damage.

[0017] In a variant of the concept of the invention which is a further development thereof however it is also possible to use a mutually displaced linear array of power ultrasonic transducer devices in the form of longitudinally vibrating compound transducer devices with amplitude transformers flange-mounted thereto, which can be supplied by way of a respective central bore with a cleaning fluid (for example surface active agents, bases, acids, enzymes, or special ultrasonic cleaning agents). The use thereof in the form of a linearly displaced array also makes it possible to efficiently clean flat objects of large surface area. In this case also two coaxially arranged sealing lips serve to hold the cleaning fluid and then suck it away. Due to the fluid cavitation effect the vibrating sonotrode is lifted by some hundredths of a millimeter from the article to be cleaned, in the manner of a hydrodynamic bearing. The surface is gently and efficiently cleaned by the high fluctuating pressures of some kilobars, which occur in the cavitation procedure.

[0018] The invention will now be described in greater detail by means of embodiments with reference to the Figures in which:

[0019]FIG. 1 shows the arrangement in principle of an ultrasonic cleaning head according to the invention, with a sonotrode in the form of a flexural vibrator,

[0020]FIG. 2 shows an at least double-shell sealing lip system for an ultrasonic cleaning head as shown in FIG. 1,

[0021]FIG. 3 shows a view of the flexural vibrator illustrated in FIG. 1, from the operative side,

[0022]FIG. 4 shows a plan view of an arrangement in the form of an array of individual round sonotrodes of an alternative embodiment, and

[0023]FIG. 5 shows an alternative configuration of a hand-guidable ultrasonic floor or wall cleaner.

[0024]FIG. 1 shows the arrangement in principle of an ultrasonic cleaning head according to the invention, comprising the ultrasonic generator 1, the ultrasonic transducer device 2 and the sonotrode 3. The supply of electrical power is effected by way of a power supply 5 and the cleaning fluid is supplied and sucked away by way of the hose system 4. In this arrangement the sonotrode 3 is in the form of a bar-shaped flexural vibrator.

[0025]FIG. 2 clearly shows the principle of at least double-shell sealing lip system 8 and 9, wherein the sonotrode 3 projects through the opening 6 into the region of the inner sealing lip ring 8 and the amount of fluid which is supplied centrally is sucked away through a peripherally extending hose and groove system 7 within the sealing lip ring 9.

[0026]FIG. 3 shows a view from the operative side of the flexural vibrator 3 shown in FIG. 1. In this case the fluid which is supplied by way of the feed conduit 4 is flushed through individual pores 11 into the region of the ultrasonic effect.

[0027]FIG. 4 shows a plan view of an arrangement in the form of an array of individual round sonotrodes within a rectangular end frame. In this case the round sonotrodes 10 are arranged within a double-shell sealing lip system 8 and 9 and also have a central fluid supply 11. The rectangular frame 7 in this case is not itself an ultrasonic vibrator but a guide aid.

[0028]FIG. 5 shows the structure in principle of a hand-guidable ultrasonic floor or wall cleaner having a handle 12 which is pivotably mounted to the unit comprising the generator 1, the ultrasonic transducer device 2 and the sonotrode 3, and which has operating means for power regulation 13, as well as an electrical connecting line 5 and a suction/flushing connecting conduit 4 to a mobile supply unit 14 which includes the power supply as well as the suction/flushing device and a filter device. The mobile supply unit 14 is connected by way of a normal mains connection 15 to the regular power supply. 

1. A cleaning apparatus for the ultrasound-aided cleaning of stationary utility surfaces, comprising an ultrasonic source (1, 2), an ultrasonic transmitter (3) connected to the ultrasonic source (1, 2), and a fluid film unit (4, 8, 9, 11) which is at least indirectly connected to the ultrasonic transmitter and which is adapted to produce and/or maintain a fluid film between the ultrasonic transmitter (3, 10) and a utility surface to be cleaned, characterised by a beam or plate vibrator (3, 10) which is coupled to the ultrasonic transmitter (3, 10) and whose resonance frequency is tuned to the frequency of the ultrasound used.
 2. A cleaning apparatus as set forth in claim 1 wherein the ultrasonic transmitter is a sonotrode (3, 10).
 3. A cleaning apparatus as set forth in one of the preceding claims wherein the beam or plate vibrator (3, 10) is releasably connected to the ultrasonic transmitter (3, 10).
 4. A cleaning apparatus as set forth in one of the preceding claims wherein the beam or plate vibrator (3, 10) is of a rectangular shape.
 5. A cleaning apparatus as set forth in claim 2 or claim 3 wherein there is provided an array of individually excited sonotrodes (10) each with a round end face.
 6. A cleaning apparatus as set forth in one of claims 1 through 4 wherein the ultrasonic transmitter is a central sonotrode (3) with a free end which is in the form of a bar-shaped flexural vibrator.
 7. A cleaning apparatus as set forth in one of the preceding claims wherein the ultrasonic transmitter is supported with the beam or plate vibrator in a frame (7) in such a way that no ultrasonic vibrations are transmitted to the frame (7).
 8. A cleaning apparatus as set forth in claim 7 wherein the beam or plate vibrator (3, 10) is fixed to the frame (7) at the locations of the vibration nodes.
 9. A cleaning apparatus as set forth in one of the preceding claims wherein the beam or plate vibrator (3, 10) has a central bore (6, 11) by way of which a fluid can be supplied.
 10. A cleaning apparatus as set forth in one of the preceding claims wherein the ultrasonic source (1, 2) has an ultrasonic generator (1) and an ultrasonic transducer device (2).
 11. A cleaning apparatus as set forth in one of the preceding claims wherein the fluid film unit has a sealing device (8, 9) which is connected to the sonotrode (3), the ultrasonic transducer device (2) and the ultrasonic generator (1) and is adapted to hold a fluid cushion between the sonotrode (3) and a utility surface to be cleaned.
 12. A cleaning apparatus as set forth in claim 11 wherein the sealing device includes a sealing lip system (8, 9) which is adapted to guide a delimited fluid cushion over a utility surface to be cleaned.
 13. A cleaning apparatus as set forth in claim 12 wherein the sealing lip system (8, 9) is an at least two-shell system.
 14. A cleaning apparatus as set forth in one of claims 11 through 13 wherein the fluid film unit includes suction removal means for sucking away excessive fluid.
 15. A cleaning apparatus as set forth in claims 12 through 14 wherein the suction removal means are provided within the sealing lip system (8, 9).
 16. A cleaning apparatus as set forth in one of the preceding claims comprising a handle (12) for easy displacement of the cleaning apparatus over a surface to be cleaned.
 17. A cleaning apparatus as set forth in one of the preceding claims comprising a power regulator (13) for ultrasonic power to be delivered.
 18. A cleaning apparatus as set forth in one of the preceding claims comprising an adjusting device for an amount of fluid to be supplied and/or sucked away.
 19. A cleaning apparatus as set forth in claim 16 and claim 17 or claim 18 wherein the power regulator (13) and/or the adjusting device is adjustable from the handle (12).
 20. A cleaning apparatus as set forth in one of the preceding claims comprising a limit value unit which is adapted to adjust and detect limit values for switching off the supply of power and fluid. 